1 Flashcards
polar
Molecule with partial charges. Mixes with water.
nonpolar
No partial charges. Do not mix with water.
electronegativity
Attraction of an atom for electrons in a covalent bond.
cohesion
Water molecules sticking to each other.
adhesion
Water molecules sticking to other surfaces.
isomers
Same atoms but different arrangement.
structural isomers
Differ in arrangement of atoms.
geometric isomer
Differ in arrangement around a double bond
enantiomers
Structures that are like a mirror-image.
alpha glucose
Monomer for starch and glycogen.
beta glucose
Monomer for cellulose and chitin.
cellulose
Carbohydrate component of plant cell walls.
starch
Storage polysaccharide of plants.
glycogen
Extremely branched polymer of glucose.
chitin
Polysaccharide found in arthropod exoskeletons and fungal cell walls.
-ose
suffix of a sugar
tryiacylglycerol
Glycerol and three fatty acids.
steroids
made of 4 rings of carbon
cholesterol
Steroid common in cell membranes, also in many hormones.
peptide bond
Bonds that connect amino acids.
Fredrick Sanger
Determined amino acid sequence of proteins.
disulphide bridges
reinforce tertiary structure
primary structure
chain of amino acids
secondary structure
Either an alpha helix or beta pleated sheet.
tertiary structure
Results from interactions between side chains.
quarternary structure
Results from two or more polypeptide subunits
-in
suffix of a protein
purines
bases w/ double-ring structure
pyrimidines
bases w/ single-ring structure
phosphodiester bonds
Bonds between phosphate group and pentose sugar in nucleic acids.
synthesis
to put together
digestion
to break apart
dehydration synthesis
Condensation reaction where molecules are connected by loss of a water molecule.
hydrolysis
Reaction where water split into two hydrogens and one oxygen; this breaks a polymer.
anabolism
Metabolic pathways that construct molecules, requiring energy.
catabolism
Metabolic pathways that break down molecules, releasing energy.
evolutionary adaptation
An accumulation of inherited characteristics that enhance organisms’ ability to survive and reproduce in specific environments.
artificial selection
Humans modifying species for desired traits through selective breeding.
descent w/ modification
Darwin’s way of referring to evolution.
MRSA
Methicillin-resistant Staphylococcus aureus.
homology
Similarity resulting from common ancestry.
homologous structures
Same structure, different function. Comes from common ancestor.
comparative embryology
Embryos of vertebrates share many anatomical homologies.
vestigial structures
Are little or no importance to organism, but remain from an ancestor.
biogeography
geographic distribution of species
microevolution
Change in genetic makeup of a population from generation to generation.
macroevolution
Evolutionary change above the species level.
population genetics
Study of allele frequency distribution and change under the influence of evolutionary processes.
Hardy-Weinberg Theorem
Helps measure changes in allele frequencies over time. Provides an “ideal” population to use as a basis of comparison.
mutation
Changes in the nucleotide sequence in DNA.
sexual recombination
Crossing over and shuffling of genes during meiosis.
genetic drift
Change in allele frequencies due to chance.
bottleneck effect
When a population has been dramatically reduced, and the gene pool is no longer reflective of the original population’s.
founder effect
When a small number of individuals colonize a new area; the new gene pool is not reflective of original population.
gene flow
When a population gains or loses alleles., movement of alleles into or out of a population due to the migration of individuals to or from the population.
genetic variation
Heritable variations in a population.
discrete characteristics
Characteristics that are classified on an either-or basis, determined by a single gene locus.
quantitative characteristics
Characteristics that vary along a continuum, usually due to influence of two or more genes.
geographic variation
Difference in variation between population subgroups in different areas.
cline
A graded change in a trait along a geographic axis.
relative fitness
Fitness of a particular genotype.
heterozygous advantage
Maintains recessive alleles in a population,
sexual selection
Natural selection for mating success.
sexual dimorphism
Differences between the sexes in secondary sexual characteristics.
speciation
Origin of new species and the source of biological diversity.
biological species concept
Species is a group of populations whose members have the potential to produce fertile offspring.
reproductive isolation
Barriers that impede members of two different species fro producing fertile offspring.
prezygotic barriers
Barriers that impede mating or hinder fertilization.
habitat isolation
When two species encounter each other only rarely.
temporal isolation
When two species breed at different times of day, season, or years.
behavioral isolation
Incompatible courtship rituals, pheromones, or bird songs.
mechanical isolation
Morphological differences prevent fertilization.
gametic isolation
When sperm can’t fertilize the eggs.
postzygotic barriers
Barriers that prevent the hybrid zygote from becoming a fertile adult.
reduced hybrid viability
When the genes of different species interact and impair hybrid development.
reduced hybrid fertility
Sterile hybrids due to uneven chromosome number.
hybrid breakdown
Hybrid is fertile, but when they breed the next generation is sterile.
allopatric speciation
When a population is divided; leads to speciation.
sympatric speciation
Speciation without a divided population.
polyploidy
In plants, the result of an extra set of chromosomes during cell division.
autopolyploid
Having more than two sets of chromosomes from a single species.
allopolyploid
Sterile hybrid is changed to a fertile polyploid due to mutation; fertile with each other, but not parent species.
adaptive radiation
Evolution of many new species from a common ancestor as a result of introduction to new environments.
punctuated equilibrium
A model of evolution in which a new species will change the most as it buds from a parent species, and then will change little for the rest of its existence.
gradualism
A model of evolution in which gradual change over a long period of time leads to biological diversity.
heterochrony
Change in the rate or timing of a developmental event; an organism’s shape depends on relative growth rate of body parts.
allometric growth
Proportioning that gives a body a specific form.
homeotic genes
Genes that determine basic features of where a body part is.
Hox genes
Class of homeotic genes. Changes in these genes can have a profound impact on morphology.
phylogeny
Evolutionary history of a species or group of species
systematics
Analytical approach to understanding the diversity and relationships of present and past organisms.
analogy
Anatomical similarity due to convergent evolution.
homoplasies
Analogous structures that have evolved independently.
taxonomy
A classification of organisms into groups based on similarities.
genus
1st part of scientific name
specific epithet
2nd part of scientific name
phylogenetic trees
Branching diagrams that depict hypotheses about evolutionary relationships.
cladogram
Diagram that shows patterns of shared characteristics
clade
A taxonomic grouping that includes only a single ancestor and all of its descendants.
cladistics
A phylogenetic classification system that uses shared derived characters and ancestry as the sole criterion for grouping taxa.
monophyletic group
A taxonomic grouping that includes an ancestral species and all of its descendants.
